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Abstract:

Presently described are dental implant articles, including kits, methods
of making dental implant articles and methods of use. The dental implant
articles (200) described herein comprise preformed dental implant
abutment (210) integrated therein. The preformed dental implant abutment
comprises a subgingival implant anchor-receiving end and an opposing end
wherein the opposing end is permanently bonded within a sufficiently
malleable dental material, which preferably comprises tooth-shaped
gingival exterior surfaces (201).

Claims:

1. A preassembled dental implant article comprising a preformed dental
implant abutment comprising a subgingival implant anchor-receiving end
and an opposing end wherein the opposing end is permanently bonded within
a hardenable sufficiently malleable dental material comprising one or
more monomers, oligomers, and/or polymerizable polymers and the dental
abutment is a different material than the sufficiently malleable
material.

2. The preassembled dental implant article of claim 1 wherein the implant
abutment is a metal abutment, a ceramic abutment, a plastic abutment, a
composite abutment, or a hybrid thereof

3. The preassembled dental implant article of claim 2 wherein at least
the opposing end of the abutment comprises a coating.

4. The preassembled dental implant article of claim 1 wherein the
opposing end comprises mechanical retention features that span at least
50% of the opposing end height.

6. The preassembled dental implant article of claim 1 wherein the
opposing end is permanently bonded within the sufficiently malleable
dental material such that the pull strength is at least 5 kg after
curing.

7. The preassembled dental implant article of claim 1 wherein the
sufficiently malleable dental material further comprises a bore for
providing access to an internal bore of the implant abutment.

8. The preassembled dental implant article of claim 1 wherein the
sufficiently malleable dental material further comprises a partial bore
or visible marking for indicating the location of an internal bore of the
implant abutment.

9. The preassembled dental implant article of claim 1 wherein the
sufficiently malleable dental material has sufficient malleability to be
formed in shape at a temperature of about 15.degree. C. to 38.degree. C.

20. The preassembled dental implant article of claim 1 wherein the
opposing end of the preformed dental abutment is permanently bonded
within the sufficiently malleable material at an interface that is free
of cement and adhesive.

21. The preassembled dental implant article of claim 1 wherein the
preassembled dental implant article is provided in a package.

22-24. (canceled)

25. A method of making a dental implant article comprising: providing a
preformed dental implant abutment having an implant anchor-receiving end
and an opposing end; providing the opposing end of the dental implant
abutment within a mold cavity, wherein the mold cavity is suitably shaped
for use as a healing cap optionally comprising tooth-shaped supragingival
exterior surfaces; filling the mold cavity with a hardenable sufficiently
malleable material comprising one or more monomers, oligomers, and/or
polymerizable polymers.

26. The method of claim 25 further comprising a liner disposed between
the mold cavity and the sufficiently malleable material.

27. A method of making a dental implant article comprising: providing a
preformed dental implant abutment having an implant anchor-receiving end
and an opposing end; forming a hole in a piece of hardenable sufficiently
malleable material comprising one or more monomers, oligomers, and/or
polymerizable polymers, the piece suitably shaped for use as a healing
cap optionally comprising tooth-shaped supragingival exterior surfaces;
providing the opposing end of the dental implant abutment within the
hole; and filling the remainder of the hole with a hardenable material.

28. The method of claim 27 further comprising providing a bore suitable
for providing access to an internal bore of the implant abutment.

29-31. (canceled)

Description:

BACKGROUND

[0001] As described for example in the Background of US 2007/0031793, a
widely-used form of dental implant fixture, includes a generally
cylindrical body which is implanted in a cylindrical bore made in the
patient's jawbone (i.e., an endosseous implant) at the site of a
edentulous ridge or tooth extraction socket, and having an
internally-threaded cylindrical socket in which to fasten components used
for attaching a permanent restoration to the implant fixture once the
jawbone and gumline are healed. Prior to healing, the abutment is
releasably fastened into cylindrical body by screwing threads into the
implant socket. Once the abutment is releasably secured in place, the
appropriately sized pre-fabricated temporary attachment is placed over
abutment such that the void is mated with abutment properly adjusted
(interproximally and occlusally), and the crown is secured in place using
a suitable temporary dental fixative. The temporary abutment and
temporary attachment may generally be left in place for period of time,
e.g., 2 months, 3 months, 6 months, etc. sufficient to allow for healing
of the patient's jawbone and gumline. Once healed, the temporary
attachment may be removed, and a permanent restoration put in place on
the implant fixture, as known in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] FIG. 1 is a perspective view of an embodied preformed dental
implant article affixed to an implant anchor and a cross-sectional view
of the adjacent dental tissue.

[0005] Even when the implant is covered with a temporary attachment such
as a provisional crown or healing cap, the gingival tissue around the
extracted tooth typically retracts losing its natural emergence profile,
leading to poor esthetics. This gingival tissue retraction is surmised to
be caused by the provisional crown or temporary attachment not being
properly sized and/or shaped relative to the extracted tooth and
subsequent permanent restoration. Often there is a locational or angular
misplacement of the implant relative to the neighboring dentition. Such
misplacement can be unintentional or intentional, dictated by the primary
consideration of available bone structure and/or function of the implant,
rather than esthetical consideration.

[0006] Accordingly, industry would find advantage in preformed dental
implant articles that can be customized in shape in order to manage the
shape of the healing (e.g. gingival and/or internal) dental tissue.

DETAILED DESCRIPTION

[0007] Presently described are dental implant articles, including kits,
methods of making dental implant articles and methods of use. The dental
implant articles described herein comprise preformed dental implant
abutment integrated therein. The preformed dental implant abutment
comprises a subgingival implant anchor-receiving end and an opposing end
wherein the opposing end is permanently bonded within a sufficiently
malleable dental material.

[0008] In some embodiments, the dental implant article may be described as
preassembled dental implant articles. In such embodiment, a preformed
dental implant abutment is permanently bonded to (a piece of)
sufficiently malleable material prior to use (e.g. as packaged) or as
received by the dental practitioner.

[0009] In other embodiment, a dental implant article is described
comprising a dental implant abutment comprising a subgingival implant
anchor-receiving end and an opposing end wherein the opposing end is
embedded within a sufficiently malleable material having tooth-shaped
gingival and subgingival exterior surfaces at an interface that is free
of cement and adhesive.

[0010] The dental implant abutment comprises a subgingival implant
anchor-receiving end and an opposing end wherein the opposing end is
permanently bonded (e.g. embedded) within a (piece of) sufficiently
malleable dental material. The opposing end may be permanently bonded by
mechanical means, chemical, means, or a combination thereof. The
sufficiently malleable dental material can be customized in shape and
hardened by curing. The dental implant abutment generally comprises a
different material than the implant abutment.

[0011] In preferred embodiments, the dental implant article comprises
substantially tooth-shaped gingival and subgingival exterior surfaces,
i.e. at least where the dental implant article contacts the gingival
tissue and internal (e.g. connective) tissue beneath the gingival tissue
for the purpose of managing the shape of the healing tissue.

[0012] In some embodiments, the dental implant article lacks tooth-shaped
supragingival exterior (i.e. external) surfaces and may be characterized
as a healing cap. In other embodiments, the dental implant article
comprises supragingival exterior (i.e. external) surfaces and may be
characterized as a (e.g. temporary or provisional) crown.

[0013] The dental implant article is advantageous in that the use thereof
is amenable to a more efficient process by eliminating the step of the
dental practitioner or dental lab cementing the (e.g. crown) restoration
or healing cap onto the implant abutment. Further, since the implant
abutment is embedded during manufacture, the interface between the
implant abutment and sufficiently malleable material can be free of
adhesive and cement.

[0014] The presence of adhesives and cements can typically be
distinguished from a restoration dental material such as a sufficiently
malleable material by qualitative analysis of the components and/or
quantitative analysis of the inorganic filler content. In some
embodiments, the interface comprises different components typically
derived from the use of different polymerizable monomers or oligomers.
When the adhesive or cement present at the interface comprises
substantially the same polymerizable material, the adhesive or cement can
typically be distinguished by its inorganic filler content. Whereas, the
sufficiently malleable material typically comprises a filler
concentration of at least 50 wt-%, or 60 wt-%, or 70 wt-%; adhesives and
cements normally have a filler content of no greater than about 30 wt-%.

[0015] Various dental implant systems, as known in the art, may be used in
combination with the methods and dental implant articles described
herein. With reference to FIGS. 1-2, dental implant systems generally
include a (e.g. cylindrical) anchor 120 and 220 that is implanted in the
patient's jawbone. The dental implant system also includes a temporary or
permanent abutment 110 and 210 that mates with the anchor and extends at
least slightly above the gum line.

[0016] The abutment may take the form of an elongated tubular body which
has a base portion adapted at a first end of the body to mate with the
gingival aspect of the implant anchor, and a solid or thin-walled tubular
portion extending to the other end of the body supragingivally from the
base portion when the base portion is so mated.

[0017] Various suitable implant abutments, as known in the art, may be
used in connection with the methods and dental implant articles described
herein, such as commercially available from Straumanns, 31, Astra tech,
Zimmer, and Nobel.

[0018] Abutments may be made with a variety of materials including metals,
(e.g. palladium-silver alloy, stainless steel, aluminum, titanium,
titanium-alloy gold etc.), plastic materials (e.g. acrylics) including
plastics that further comprise an inorganic filler; and ceramic materials
such as those comprising zirconia and aluminum oxide, etc. Composite
abutments can be made using a mixture of these materials. For example, a
filled plastic is a composite material.

[0019] In some embodiments, the implant abutment is a preformed (e.g. one
piece) abutment having a (e.g. hex-shaped) implant (e.g. anchor)
receiving end and an opposing end. Alternatively, the implant abutment
may be a (e.g. metal/ceramic) hybrid abutment. For example, the implant
abutment may comprise a preformed metal abutment that is an abutment
interface having an implant-receiving end for attachment to a tooth
implant (e.g. anchor) and an opposing end comprising a ceramic abutment
"top" as can be prepared from Lava® Zirconia available from 3M ESPE.
Unless specifically stated otherwise, the term "implant abutment" as used
herein also encompasses implant abutment interfaces having an abutment as
well.

[0020] Hence the implant abutment may be a metal abutment, a ceramic
abutment, a plastic abutment, a composite abutment, or a hybrid thereof.

[0021] With reference to FIG. 3, a perspective view of an illustrative
preformed implant abutment (e.g. interface), the implant abutment may
take the form of an elongated tubular body generally comprising a (e.g.
hex shaped) base end 155 that is designed to mate with the implant (e.g.
anchor) and an opposing end 153. The opposing end typically includes a
subgingival portion, a gingival portion, as well as a supragingal
portion. The opposing end is embedded within the sufficiently malleable
material.

[0022] The implant abutment is typically provided within the sufficiently
malleable material such that the platform 160 and opposing end above such
platform are contacting the sufficiently malleable material. The
subgingival implant-receiving end of the implant is typically exposed.
The subgingival implant-receiving end typically protrudes from the outer
surface of the piece of sufficiently malleable material. Abutments that
include a platform are commercially available from Nobel Biocare under
the trade designation "Easy Abutment".

[0023] Alternatively, the abutment may lack a platform. In such
embodiment, the base of the sufficiently malleable portion may rest
directly on the implant anchor. Exemplary abutments that lack a platform
are commercially available from Straumann ITI.

[0024] Abutments comprising external threads to mate with internal threads
of the implant anchor have been described in the art, such as depicted in
US 2010/0151423. Such design is suitable for embodiments wherein a dental
article (such as a healing cap or temporary crown) are affixed to the
implant abutment after the implant abutment has been mechanically
attached to the implant anchor, such as described in PCT/US2010/022961.
However, due to the fact that the entire abutment needs to be rotated in
order to engage the threads of the abutment with the anchor, it is
appreciated that the supragingival portion may contact neighboring teeth
during such rotation. Further misalignments with the oral cavity are
likely to occur, particularly when the material is cured prior to the
dental implant article being mechanically attached to the underlying
anchor.

[0025] In one favored embodiment, (such as depicted in FIG. 2) the
abutment comprises a shoulder (not shown) within the cavity for
cooperation with a screw 250 to fasten the abutment to the implant
anchor. Since the abutment is mechanically attached to the underlying
implant anchor with a screw, the entire abutment need not be rotated in
order to attach the abutment to the implant anchor.

[0026] For embodiments wherein the implant abutment comprises a shoulder
within the cavity for cooperation with a screw 250 to fasten the abutment
to the implant anchor, the (e.g. self-supporting) piece of sufficiently
malleable material further comprises a vertical bore, as depicted in FIG.
2 for providing access to an internal bore of the implant abutment. As
depicted, the vertical bore extends the entire height of the sufficiently
malleable material (top) portion. Although such vertical bore 230 may be
created after fabrication, such as by drilling, it is preferable to
provide a (e.g. preassembled) dental implant article wherein the internal
bore is already present. In one embodiment, such internal bore is created
during the molding of the piece of sufficiently malleable material by
including such cylindrical-shaped structure within the mold cavity
design. Since this internal bore is filled with a material, after
attaching the dental implant article to the implant anchor, such internal
bore need not be precisely formed. The internal bore may be filled with
additional sufficiently malleable material, and more typically a
different (e.g. low viscosity) curable dental restoration material such
as commercially available from 3M ESPE under the trade designation
"Filtek Supreme Plus Flowable Restorative". Vertical bores (also referred
to as an interior cavity) 230, that are substantially conical or
cylindrical in shape can accommodate a wide variety of implant designs.

[0027] With reference to FIG. 2, the width ("w") of the interior cavity
(i.e. vertical bore) at the base of the sufficiently malleable portion of
the dental implant article typically ranges from about 2 mm to about 6
mm, (e.g., 2.5 mm, 3.3 mm, 3.5 mm, 4.0 mm, 4.1 mm, 4.3 mm, 4.8 mm, 5.0
mm, 6.0 mm etc.) Suitable heights ("h") for such cavity may be configured
to match known implant abutment heights. Typically, the height is at
least about 10 mm and no greater than about 20 mm. Abutment interfaces
are typically shorter, having a height of at least about 3 mm.

[0028] In one embodiment, the preformed dental implant article comprises
an interior cavity (i.e. vertical bore) and the thickness ("t") of the
dental implant article between the cavity and apical (i.e. highest point
relative to the base) gingival exterior surface 201 is preferably at
least 1 mm (except in the case of a lower incisor or lower lateral). When
the sufficiently malleable portion of the dental implant article
comprises a convex gingival surface, the apical gingival exterior surface
may be characterized by the onset of curvature. In some embodiments, the
thickness ("t") may be at least 1.1, 1.2, 1.3, or 1.4 mm. In the case of
premolars, the thickness is typically at least 1.50 mm. In some
embodiments, the thickness ("t") may be at least 1.6, 1.7, 1.8, or 1.9
mm. For molars, this thickness is typically at least 2, 2.5, or 3 mm.

[0029] In some embodiments, the dental implant article comprises
tooth-shaped supragingival exterior surfaces. When the dental implant
article is substantially tooth-shaped above the gum line, the dental
implant article may serve as a permanent rather than temporary
restoration.

[0030] The exterior geometry of implant abutments have previously been
designed in consideration of the fabrication of subsequently seated (e.g.
crown) restorations. Hence, for embodiments wherein currently
commercially available implant abutments are embedded into the
sufficiently malleable material, the supragingival exterior surfaces of
the abutment are generally free of any structural features that would
detract from the fit between the exterior surface of the abutment and the
restorative. Hence, the supragingival exterior surfaces of (commercially
available) abutments are generally free of undercuts, as well as deep
(e.g. horizontal) grooves or protrusions (e.g. having a difference in
depth of about 0.1 mm or greater).

[0031] However, since it is presently described to embed the supragingival
end of the implant abutment within the sufficiently malleable material
prior to use, the presence of undercuts and deep grooves can be present
and may be advantageous for the purpose of mechanically bonding the
implant abutment within the surrounding sufficiently malleable material.

[0032] As depicted in FIG. 3, the supragingival end of the implant
abutment preferably comprise one or more (anti-pull) retention features,
such as (e.g. shallow) grooves that hinder removal of the abutment from
the sufficiently malleable material portion. In some embodiments, such
(anti-pull) retention features have a depth no greater than about 0.1 mm.
Other (anti-pull) retention features include for example shallow
horizontal flat(s), horizontal groove(s), or horizontal protrusion(s).
Alternatively or in addition to mechanical retention features, the
supragingival end of commercially available implant abutment can be
mechanically or chemically surface modified to improve adhesive.

[0033] Such (e.g. shallow) mechanical features and/or other surface
modification can increase the surface area and mechanically interlock
with the surrounding sufficiently malleable material, particularly upon
curing the sufficiently malleable material.

[0034] In some embodiments, the (supragingival) opposing end is roughened
for example for sandblasting. The surface roughness (Ra) of the uncoated
abutment may be about 1 for a metal abutment that has not been subjected
to surface roughening. A sandblasted metal abutment may have a surface
roughness (Ra) of about 2 to 3. As the roughness increases, the bond
strength between the abutment and sufficiently malleable material or
other (e.g. dental restoration) material at the abutment interface can
also increase.

[0035] In some embodiments, the (supragingival) opposing end of the
implant abutment comprises a coating that increases the surface roughness
and/or improves the adhesion with the sufficiently malleable material
(without substantially changing the surface roughness). In one
embodiment, such as when the dental implant abutment is a metal implant
abutment or made from some other material that is not tooth-colored, it
may be advantageous to coat at least the supragingival surfaces with an
opaque (e.g. tooth-colored) coating to mask the appearance of the
preformed metal abutment, thereby improving the aesthetic appearance of
the dental (e.g. healing cap or crown) restoration, such as described in
Pending U.S. Application Ser. No. 61/242,546, filed Sep. 15, 2009. Such
coatings generally comprise a polymeric binder and at least one opaque
filler and/or pigment. The inclusion of the coating can alter the
reflection properties of a metal abutment. The coating can increase the
total reflection of the metal abutment such that the total reflection is
at least 25%, 30%, 40%, 45%, 50%, or 55% at wavelengths of visible light.
Such coating can also increase the roughness of the coated implant
abutment. For example, the coated surfaces of the abutment may have a
surface roughness, Ra, of at least 3 and more preferably at least 4, 5,
or 6. In some embodiments, the surface roughness is at least 10, 15, or
20.

[0036] In another embodiment, the opposing (supragingival) end of the
implant abutment comprises a coating of a dental restoration. One
suitable dental restoration material is the previously described "Filtek
Supreme Plus Flowable Restorative".

[0037] In some embodiments, the coating is applied to the implant abutment
and cured prior to embedding or otherwise permanently bonding the
opposing end of the implant abutment within the sufficiently malleable
material. In other embodiments, the packaged dental implant article
comprises an uncured or only partially cured coating between the abutment
interface and the sufficiently malleable material. The coating is cured
concurrently with the curing of the sufficiently malleable material after
shaping of the sufficiently malleable material.

[0038] Regardless of design, the implant abutment generally comprises a
gingival (e.g. platform) section between the subgingival and
supragingival ends of the implant abutment. Further, the supragingival
end protrudes into the sufficiently malleable material, having a
contacting surface area greater than a cross-section (area) of implant
abutment at the gingival section. The increase in surface area can vary
depending on the type of dental implant article. The increase in surface
are can be at least 10%, 20%, 30%, 40%, 50%, or greater, particularly
when the dental restoration is a crown.

[0039] Implant abutments typically comprise one or more anti-rotation
features as known in the art. For example, the subgingival end of the
abutment that mates with the implant (e.g. anchor) are typically
hexagonal 155 in shape that can prevent the rotation of the implant
abutment within the bore of the implant (e.g. anchor). The
(supragingival) opposing end of the implant abutment may also comprise
one or more anti-rotation features that can prevent rotation of the
implant abutment within the sufficiently malleable material. The
(supragingival) opposing end may include for example vertical flat(s),
vertical groove(s), or vertical protrusion(s).

[0041] The sufficiently malleable portion of the preformed dental implant
article preferably comprises a convex gingival exterior surface 201.
Particularly for molar implants, the sufficiently malleable portion of
the dental implant article further comprises a convex subgingival
exterior surface 205. Hence, the exterior surface may be continuously
convex from the gingival exterior surface to the substantially planar
base exterior surface that contacts the implant abutment (platform 160 of
FIG. 1). Although the radius of curvature of this convex surface can
vary, the radius of curvature is typically at least 2 mm and no greater
than 10 mm. Alternatively, such as in the case of incisors the
subgingival exterior surfaces of the sufficiently malleable portion of
the dental implant article may comprise a slight concavity (not shown).

[0042] In some embodiments, such as depicted by the FIG. 2, the dental
implant article comprises substantially tooth-shaped exterior surfaces
both below and above the gum line. For example, the shape may take the
form of a natural maxillary or mandibular tooth, including anterior
crowns (i.e. central incisor, lateral incisor, canine), premolar, or
molar tooth. This can be accomplished by preforming the dental implant
article such that the exterior surfaces comprise both subgingival and
supragingival tooth-shaped exterior surfaces.

[0043] In other embodiments, such as depicted by the dental implant
article 105 outlined by the dashed lines of FIG. 1, the (e.g. temporary)
dental article may be predominantly a healing cap. In such embodiment, a
preformed dental implant article is described wherein the supragingival
exterior surfaces substantially lack a tooth-shaped structure and at
least the exterior surfaces (e.g. that contact the healing gum tissue)
comprise a sufficiently malleable such that it can be customized in shape
and hardened. A crown 106 having substantially tooth-shaped supragingival
exterior surfaces can be affixed to the dental implant article 105 with a
dental cement as known in the art. Typically, the cavity 230 of the
dental crown article is partially filled with a dental cement and then
placed over the healing cap such that the base of the crown contacts the
abutment platform 160. A temporary dental cement is typically used for
embodiments wherein the crown is affixed temporarily. Suitable temporary
cements are commercially available such as available from 3M ESPE under
the trade designation "RelyX Temp NE Temporary Cement". A permanent
dental cement, such as commercially available from 3M ESPE under the
trade designation "RelyX Unicem Self Adhesive Universal Resin Cement", is
employed for embodiments wherein the crown is a permanent dental article
and functions as a permanent restoration.

[0044] In other embodiments, kits are described comprising a single dental
implant article or a plurality of dental implant articles optionally in
combination with other dental articles employed during a tooth implant
procedure.

[0045] The dental implant articles may correspond in size and shape to
natural teeth selected from the group consisting of maxillary and
mandibular central incisors, lateral incisors, canines, premolars, and
molar teeth. The kit may comprise dental implant articles of more than
one shade of tooth color, in order to select a dental implant article
that closely matches the patent's natural teeth. The kit may further
include or be combined with other article employed during a tooth implant
procedure such as an implant anchor.

[0046] The dental implant articles described herein can be used in method
of treatment, such as described in PCT/US2010/022961; incorporated herein
by reference. In one embodiment, a method of affixing a dental implant
article to an implant anchor is described. The method generally comprises
providing a preformed (e.g. temporary or permanent) dental implant
article and affixing the dental implant article to an implant anchor. In
one embodiment, the method comprises providing a preformed dental implant
article comprised of a sufficiently malleable material such that at least
the exterior portion can be customized in shape; shaping at least a
portion of the dental article that contacts gingival tissue or internal
tissue beneath the gingival tissue; affixing the dental implant article
to an implant anchor such that the sufficiently malleable portion
contacts the gingival tissue and internal tissue; and hardening at least
the sufficiently malleable portion of the dental article. The
sufficiently material may be hardened by photocuring.

[0047] Typically, the dental implant article is attached after extraction
of a tooth and prior to healing of the gingival and internal tissue.

[0048] As known in the art, the gingival sulcus is bound by the enamel of
the crown of a tooth and the sulcular gingival epithelium. The junctional
epithelium attaches to the surface of the tooth with hemideosomes and
lies immediately apical to the sulcular epithelium. The sulcular
epithelium lines the gingival sulcus from the base to the free gingival
margin, wherein it interfaces with the epithelium of the oral cavity.
Damage to the junctional epithelium can result in this tissue having an
irregular rather than smooth texture thereby forming a "pocket", a
primary symptom of gum disease.

[0049] Accordingly, to avoid damaging the junctional epithelium,
restorative crowns are generally affixed to a natural tooth surface or
healed implant abutment such that the exterior (i.e. external) surfaces
of the crown contact the sulcular gingival tissue, but not the junctional
epithelium.

[0050] FIG. 1 depicts a perspective view of an embodied preformed dental
implant article affixed to an implant abutment and a cross-sectional view
of the adjacent dental tissue. FIG. 1 is representative of affixing a
preformed dental implant article having an embedded abutment (e.g.
immediately) after extraction of a tooth and prior to healing of the
gingival and internal tissue. The method described herein comprises
affixing a preformed dental implant article 105 to an implant anchor 120
such that exterior surfaces of the dental implant article contact
sulcular gingival epithelium tissue 170 and internal tissue beneath (e.g.
covered or concealed by) the gingival tissue. The internal tissue
contacting the exterior surface of the dental implant article may include
the junctional epithelium 175. Typically, however, the junctional
epithelium may also be removed during the tooth extraction. More
typically, the sufficiently malleable portion of the dental implant
article is in contact with connective tissue 180 which is disposed
between the gingival tissue 170 and jaw bone tissue 190. The internal
tissue(s) in contact with the sufficiently malleable portion are
typically above the cortical plate 185. It is appreciated that the
specific type of tissue in contact with the exterior surfaces of the
dental implant article may change as a result of the healing process.
Nonetheless, the dental implant article is in contact with internal
dental tissue beneath the gingival tissue.

[0051] The method further comprises shaping at least a portion of the
sufficiently malleable material that contacts gingival tissue 170 or
internal (e.g. connective 180) tissue beneath the gingival tissue and
hardening at least the sufficiently malleable material. The method may
also entail curing a second (i.e. different) curable dental material that
may be present. For example, in some embodiments the (e.g. metal) dental
implant abutment or interface is coated with a curable dental restoration
material for the purpose of improving adhesion with the (e.g. metal)
dental implant abutment or interface. This second curable dental
restoration material is concurrently cured along with the sufficiently
malleable material. By use of a dental implant article comprised of a
sufficiently malleable material, the dental implant article can be
subsequently customized in shape. Typically, such shaping occurs under a
moderate force (i.e., a force that ranges from light finger pressure to
that applied with manual operation of a small hand tool, such as a dental
composite instrument). The preformed shape in combination with the
customization thereof can manage the shape of at least the gingival
tissue during the healing of the implant. When the preformed dental
implant article is comprised of a sufficiently malleable material, as
described herein, the dental implant article can be optimized in shape
such that the optimized shape obstructs the recession of the gingival
tissue and guides the gingival tissue to heal in a shape substantially
the same as the natural emergence profile. Doing so can eliminate the
need for tissue adjustment via electro surgery or scalpel as well as
prevent blanching and impingement of soft tissue at the final restoration
stage. At the time of a tooth extraction, the sufficiently malleable
material can be optimized in shape to conform to the shape of the
resulting socket. However, when a dental implant procedure to replace a
tooth that has been missing for sufficient time that the gum tissue has
already recessed or begun to recess, the sufficiently malleable material
can be used in combination with surgical procedures to recreate the
natural emergence profile of the surrounding gum tissue.

[0052] The shaping of the sufficiently malleable portion of the dental
implant article typically occurs prior to affixing the dental implant
article to the implant anchor. However, the dental implant article can
alternatively or additionally be shaped after affixing the dental implant
article to the implant anchor, yet prior to hardening (e.g. by
photocuring). Particularly for this later embodiment, the dental implant
article preferably comprises a cylindrical or conical shaped cavity to
provide access for a screw for attaching the dental implant article to
the underlying implant anchor with a screw, as previously described.

[0053] After the dental implant article has been affixed (i.e.
mechanically attached to the anchor), shaped, and hardened, the method
further comprises allowing the gingival tissues to heal. Once the anchor
120 of the implant has osseointegrated into the jaw bone, which typically
takes 2 to 6 months, the temporary dental implant article is typically
replaced with a permanent restoration such as a permanent crown or
bridge, as known in the art. Alternatively, the method described herein
can also be employed with a two-step implant method. As known in the art,
the two-step method entails suturing the skin over the head of the
implant in the area of the implant wound after surgery to allow for
healing of the patient's jawbone and gumline. Once the implant has
osteointegrated into the jaw bone, the healed dental tissue above the
tooth implant is surgically removed in order to expose the head of the
implant for receipt of a temporary or permanent crown. Accordingly, when
the two-step method is employed, the method further comprises removing
(healed) dental tissue above the tooth implant abutment or anchor such
that gingival tissue, internal tissue, and the tooth implant anchor are
exposed prior to affixing the dental implant article.

[0054] When the dental implant article is a temporary article, such as a
healing cap, the method typically further comprises allowing the gingival
and internal tissue to heal and replacing the dental implant article with
a permanent restoration.

[0055] In another embodiment, a method of providing a permanent
restoration for a tooth implant is described. The method comprises
removing a temporary dental implant article from an implant anchor,
wherein the temporary dental implant article contacts the internal tissue
beneath the gingival tissue and is formed from a hardened photocured
material; and affixing a permanent restoration to the implant anchor.

[0057] The preformed (e.g. temporary) dental implant articles are prepared
from a hardenable material that can be customized in shape to
specifically mate to the gingival and/or internal tissue beneath the
gingival tissue. The preformed dental implant articles (of a first shape)
are preferably prepared from a hardenable self-supporting resin system
with sufficient malleability to be subsequently customized into a second
shape.

[0058] Herein, the "resin system" can include one or more resins, each of
which can include one or more monomers, oligomers, and/or polymerizable
polymers.

[0059] The term "self-supporting" means that the composition is
dimensionally stable and will maintain its shape (e.g., preformed shape
of a cap) without significant deformation at room temperature (i.e.,
about 20° C. to about 25° C.) for at least about two weeks
when free-standing (i.e., without the support of packaging or a
container). Preferably, the compositions are dimensionally stable at room
temperature for at least about one month, and more preferably, for at
least about six months. Preferably, the compositions are dimensionally
stable at temperatures above room temperature, more preferably up to
about 40° C., even more preferably up to about 50° C., and
even more preferably up to about 60° C. This definition applies in
the absence of conditions that activate the initiator system and in the
absence of an external force other than gravity.

[0060] The term "sufficient malleability" means that the material or
self-supporting structure formed from the material is capable of being
custom shaped and fitted, for example, to a patient's mouth, under a
moderate force (i.e., a force that ranges from light finger pressure to
that applied with manual operation of a small hand tool, such as a dental
composite instrument). In some embodiments, the material or
self-supporting preformed structure has sufficient malleability to be
reformed into a second shape at temperature of 40° C. of less. In
some preferred embodiments, the hardenable composition exhibits
"sufficient malleability" at a temperature of about 15° C. to
38° C., a temperature of about 20° C. to 38° C., or
at room temperature.

[0061] In many embodiments, the hardenable compositions of the preformed
dental implant articles described herein are "irreversibly hardenable"
which, as used herein, means that after hardening such that the
composition loses its malleability it cannot be converted back into a
malleable form without destroying the external shape of the dental
article. Examples of some potentially suitable hardenable compositions
that may be used to construct the preformed dental implant article
described herein with sufficient malleability may include, e.g.,
hardenable organic compositions (filled or unfilled), polymerizable
dental waxes, hardenable dental compositions having a wax-like or
clay-like consistency in the unhardened state, etc. In some embodiments,
the preformed dental articles are constructed of hardenable compositions
that consist essentially of non-metallic materials.

[0062] Examples of hardenable organic compositions (filled or unfilled)
include various dental restoration materials including for example
packable composites commercially available under the trade designations
"Solitaire" from Heraeus Kulzer (Hanau, Germany); "ALERT" from
Jeneric-Pentron (Wallingford, Conn.); "SureFil" from Dentsply/Caulk
(York, Pa.); "Prodigy Condensable" from Kerr (Orange, Calif.); posterior
composite material commercially available under the trade designations
"Filtek P60 Posterior Restorative" from 3M ESPE; and universal composites
commercially available under the trade designations "Venus diamond" from
Heraeus Kulzer and "Filtek Supreme Ultra" from 3M ESPE. In some
embodiments, such hardenable organic compositions may be self-supporting.
In other embodiments, such hardenable organic compositions are not
self-supporting.

[0063] Suitable hardenable compositions that may be used to manufacture
the preformed dental implant articles are described in U.S. Pat. No.
7,674,850, titled HARDENABLE SELF-SUPPORTING STRUCTURES AND METHODS
(Karim et al.). Other suitable hardenable compositions may include those
described in U.S. Pat. No. 5,403,188 (Oxman et al.); U.S. Pat. No.
6,057,383 (Volkel et al.); and U.S. Pat. No. 6,799,969 (Sun et al.); each
incorporated herein by reference.

[0064] Organogelators described in WO2008/033911, incorporated herein by
reference, can be utilized in combination with the hardenable
compositions and/or interior marterials in the dental implant articles
described herein. These organgelator compositions can be flowable,
packable, or self-supporting. The term "organogelator" means a low
molecular weight compound (generally no greater than 3000 grams per mole)
that forms a three-dimensional network structure when dissolved in an
organic fluid, thereby immobilizing the organic fluid and forming a
non-flowable thermally-reversible gel. In some embodiments the
organogelator is a urea-type organogelator, a sugar-based compound, or a
mixture thereof. Suitable sugar-based compounds include amino sugar
organogelator, dibenzylidene sorbitol, alpha-manno(methyl
4,6,-O-benzylidene-alpha-D-mannopyranoside, or a mixture thereof.

[0065] In some embodiments, the hardenable self-supporting compositions
have rheological properties similar to waxes below the waxes' melting
points in that they can be relatively easily deformed (i.e., they are
malleable) and exhibit low elastic recovery. The compositions are
typically not free-flowing fluids (i.e., liquids) above their softening
points. That is, the compositions can display appreciable mass flow under
moderate (e.g., hand) pressure, but not liquid flow above their softening
points.

[0066] Typically, elastic and viscous dynamic moduli of the hardenable
compositions vary over a wide range. Furthermore, the hardenable
compositions are typically largely free from tack. Preferably, the
elastic dynamic modulus (i.e., elastic modulus) G' is at least about 100
kilopascals (kPa), more preferably, at least about 200 kPa, and most
preferably, at least about 1000 kPa, at a frequency of about 0.005 Hz.
Preferably, the elastic modulus G' is no greater than about 50,000 kPa,
more preferably, no greater than about 10,000 kPa, and most preferably,
no greater than about 5000 kPa, at a frequency of about 0.005 Hz.
Preferably, the viscous dynamic modulus (i.e., viscous modulus) G'' is at
least about 50 kPa, more preferably, at least about 200 kPa, and most
preferably, at least about 1000 kPa, at a frequency of about 0.005 Hz.
Preferably, the viscous modulus G'' is no greater than about 50,000 kPa,
more preferably, no greater than about 10,000 kPa, and most preferably,
no greater than about 5000 kPa, at a frequency of about 0.005 Hz.

[0067] The desired self-supporting (i.e., free-standing) structure of the
hardenable compositions can typically be maintained by creating a
morphology that includes a noncovalent structure, which may be a
three-dimensional network (continuous or discontinuous) structure. This
can result from the use of a crystalline component in the resin system,
or the use of one or more fillers, typically aided by one or more
surfactants, or the use of both a crystalline component and one or more
fillers optionally combined with one or more surfactants. These
components are discussed in more detail below.

[0068] With the appropriate initiator system, e.g., a free radical
photoinitiator, the hardenable compositions can be hardened (e.g., cured)
to form the desired product. Preferably, the resultant hardened
composition (i.e., the hardened structure) has a flexural strength of at
least about 25 megapascals (MPa), more preferably, at least about 40 MPa,
even more preferably, at least about 50 MPa, and most preferably, at
least about 60 MPa.

[0069] In some embodiments, the resultant hardened composition is an
enamel-like solid, preferably having a compressive strength of at least
about 100 MPa and/or a diametral tensile strength of at least about 20
MPa and/or a flexural modulus of at least about 1000 MPa.

[0070] The resin system includes one or more hardenable organic resins
capable of forming a hardened material having sufficient strength and
hydrolytic stability to render them suitable for use in the oral
environment.

[0071] As used herein, a resin includes one or more monomers, oligomers,
and/or polymerizable polymers, including combinations thereof. Although,
in this context oligomers and polymers are both used, the terms "polymer"
and "polymeric" are used herein to refer to any materials having 2 or
more repeat units, thereby encompassing oligomers. Thus, unless otherwise
specified, polymers include oligomers. Furthermore, the term polymer is
used herein to encompass both homopolymers and copolymers, and the term
copolymer is used herein to encompass materials with two or more
different repeat units (e.g., copolymers, terpolymers, tetrapolymers)

[0072] A preferred organic resin is hardenable (e.g., polymerizable and/or
crosslinkable), preferably by a free radical mechanism, and includes
monomers, oligomers, and/or polymers. The resin system includes a
reactive component (i.e., a component capable of polymerizing and/or
crosslinking), which may or may not be crystalline. Resin systems that
include noncrystalline reactive components may optionally include a
crystalline component, which may or may not be reactive.

[0073] Preferably, at least some of the resin components include ethylenic
unsaturation and are capable of undergoing addition polymerization. A
suitable resin preferably includes at least one ethylenically unsaturated
monomer (i.e., includes at least one carbon-carbon double bond).

[0075] Preferably, the total amount of the resin system is at least about
10 wt-%, more preferably, at least about 13 wt-%, and most preferably, at
least about 15 wt-%, based on the total weight of the composition.
Preferably, the total amount of the resin system is no greater than about
60 wt-%, more preferably, no greater than about 50 wt-%, and most
preferably, no greater than about 40 wt-%, based on the total weight of
the composition.

[0077] In some embodiments, the resin system can also include a
crystalline component to impart the noncovalent three-dimensional
structure for maintaining the initial preformed shape such as described
in U.S. Pat. No. 7,674,850; incorporated herein by reference. This
crystalline component may or may not have a reactive group capable of
polymerizing (also including crosslinking) Preferably, the crystalline
component is polymerizable. Preferably, the crystalline component is
polymeric (including oligomeric). More preferably, the crystalline
component is a polymerizable polymeric material.

[0078] By "crystalline" it is meant that the material displays a
crystalline melting point at 20° C. or above when measured in the
composition by differential scanning calorimetry (DSC). The peak
temperature of the observed endotherm is taken as the crystalline melting
point. The crystalline phase includes multiple lattices in which the
material assumes a conformation in which there is a highly ordered
registry in adjacent chemical moieties of which the material is
constructed. The packing arrangement (short order orientation) within the
lattice is highly regular in both its chemical and geometric aspects.

[0079] The crystalline resin component includes at least one material that
crystallizes, preferably above room temperature (i.e., 20° C. to
25° C.). Such crystallinity, that may be provided by the
aggregation of crystallizable moieties present in the component (e.g.,
when the component is a polymer, in the backbone (i.e., main chain) or
pendant substituents (i.e., side chains) of the component), can be
determined by well known crystallographic, calorimetric, or
dynamic/mechanical methods. This component imparts to the resin system at
least one melting temperature (Tm) as measured experimentally (for
example by DSC) of greater than about 20° C. Preferably, this
component imparts a T. sub. m to the resin system of about 30°
C-100° C. If more than one crystalline material is used in the
crystalline component, more than one distinct melting point may be seen.

[0082] Examples of suitable crystalline polymeric materials having
crystallizable pendant moieties (i.e., side chains) include, but are not
limited to polymeric materials having the following general formula:

##STR00001##

wherein R is hydrogen or a (C1-C4)alkyl group, X is
--CH2--, --C(O)O--, --O--C(O)--, --C(O)--NH--, --HN--C(O)--, --O--,
--NH--, --O--C(O)--NH--, --HN--C(O)--0--, --HN--C(O)--NH--, or
--Si(CH3)2--, m is the number of repeating units in the
polymer, and n is great enough to provide sufficient side chain length
and conformation to form polymers containing crystalline domains or
regions. Preferably, m is at least 2, and more preferably, 2 to 100, and
preferably, n is at least 10. The crystalline polymeric materials may be
prepared by the polymerization of monomers containing the pendant (side
chain) crystallizable moieties or by the introduction of pendant
crystallizable moieties by chemical modification of a polyacrylate,
polymethacrylate, polyacrylamide, polymethacrylamide, polyvinyl ester, or
poly-alpha-olefin polymers or copolymers. The preparation and
morphology/conformational properties that determine the crystalline
character of such side chain crystallizable or "comb-like" polymers are
reviewed by Plate and Shibaev, "Comb-Like Polymers. Structure and
Properties," Journal of Polymer Science, Macromolecular Reviews, 8,
117-253 (1974).

[0083] Another crystalline component includes compounds of the formula:

[0084] Fillers for use in the filler system may be selected from a wide
variety of conventional fillers for incorporation into resin systems.
Preferably, the filler system includes one or more conventional materials
suitable for incorporation in compositions used for medical applications,
for example, fillers currently used in dental restoration compositions.
Thus, the filler systems used in the compositions are incorporated into
the resin systems, and particularly mixed with the crystalline component
of the resin system.

[0085] Fillers may be either particulate or fibrous in nature. Particulate
fillers may generally be defined as having a length to width ratio, or
aspect ratio, of 20:1 or less, and more commonly 10:1 or less. Fibers can
be defined as having aspect ratios greater than 20:1, or more commonly
greater than 100:1. The shape of the particles can vary, ranging from
spherical to ellipsoidal, or more planar such as flakes or discs. The
macroscopic properties can be highly dependent on the shape of the filler
particles, in particular the uniformity of the shape.

[0086] Preferred particulate filler is finely divided and has an average
particle size (preferably, diameter) of less than about 10 micrometers
(i.e., microns). Preferred micron-size particulate filler has an average
particle size of at least about 0.2 microns up to 1 micrometers.
Nanoscopic particles have an average primary particle size of less than
200 nm (0.2 microns). The filler can have a unimodal or polymodal (e.g.,
bimodal) particle size distribution.

[0087] Micron-size particles are very effective for improving post-cure
wear properties. In contrast, nanoscopic fillers are commonly used as
viscosity and thixotropy modifiers. Due to their small size, high surface
area, and associated hydrogen bonding, these materials are known to
assemble into aggregated networks. Materials of this type ("nanoscopic"
materials) have average primary particle sizes (i.e., the largest
dimension, e.g., diameter, of unaggregated material) of no greater than
about 1000 nanometers (nm). Preferably, the nanoscopic particulate
material has an average primary particle size of at least about 2
nanometers (nm), and preferably at least about 7 nm. Preferably, the
nanoscopic particulate material has an average primary particle size of
no greater than about 50 nm, and more preferably no greater than about 20
nm in size. The average surface area of such a filler is preferably at
least about 20 square meters per gram (m2/g), more preferably, at
least about 50 m2/g, and most preferably, at least about 100
m2/g.

[0088] The filler can be an inorganic material. It can also be a
crosslinked organic material that is insoluble in the polymerizable
resin, and is optionally filled with inorganic filler. The filler is
preferably generally non-toxic and suitable for use in the mouth. The
filler can be radiopaque, radiolucent, or nonradiopaque. Fillers as used
in dental applications are typically ceramic in nature.

[0090] Examples of suitable organic filler particles include filled or
unfilled pulverized polycarbonates, polyepoxides, and the like. Preferred
filler particles are quartz, submicron silica, and non-vitreous
microparticles of the type described in U.S. Pat. No. 4,503,169
(Randklev). Mixtures of these fillers can also be used, as well as
combination fillers made from organic and inorganic materials.

[0091] Optionally, the surface of the filler particles may be treated with
a surface treatment, such as a silane-coupling agent, in order to enhance
the bond between the filler and the resin system. The coupling agent may
be functionalized with reactive curing groups, such as acrylates,
methacrylates, and the like.

[0092] The filler particles used to impart a noncovalent structure can be
composed of silica, alumina, zirconia, titania, or mixtures of these
materials with each other or with carbon. In their synthesized state,
these materials are commonly hydrophilic, due to the presence of surface
hydroxyl groups. However, the materials may also be modified by treatment
with appropriate agents, such as alkyl silanes, in order to modify this
character. For example, the surface of a filler particle may be rendered
neutral, hydrophobic, or reactive, depending on the desired properties.
Fumed silica is a preferred compound for imparting self-supporting
character, due to its low cost, commercial availability, and wide range
of available surface character.

[0093] Preferably, the total amount of filler system is greater than 50
wt-%, more preferably, greater than 60 wt-%, and most preferably, greater
than 70 wt-%, based on the total weight of the composition. If the filler
system includes fibers, the fibers are present in an amount of less than
20 wt-%, based on the total weight of the composition. Preferably, the
total amount of filler system is no more than about 95 wt-%, and more
preferably, no more than about 80 wt-%, based on the total weight of the
composition.

[0094] The compositions also contain an initiator system, i.e., one
initiator or a mixture of two or more initiators, which are suitable for
hardening (e.g., polymerizing and/or crosslinking) of the resin system.
Various suitable initiator systems are known in the art, such as
described in U.S. Pat. No. 7,674,850.

[0095] The initiators are preferably free radical initiators, which may be
activated in a variety of ways, e.g., heat and/or radiation. Thus, for
example, the initiator system can be a thermal initiator system (e.g.,
azo compounds and peroxides), or a photoinitiator system. Preferably, the
initiator system includes one or more photoinitiators. More preferably,
the initiator system includes at least one photoinitiator active in the
spectral region of about 300 nanometers (nm) to about 1200 nm and capable
of promoting free radical polymerization and/or crosslinking of
ethylenically unsaturated moieties upon exposure to light of suitable
wavelength and intensity. A wide variety of such photoinitiators can be
used. The photoinitiator preferably is soluble in the resin system.
Preferably, they are sufficiently shelf stable and free of undesirable
coloration to permit storage and use under typical dental operatory and
laboratory conditions. Visible light photoinitiators are preferred.

[0096] Preferred visible light-induced initiators include camphorquinone
combined with a suitable hydrogen donor (e.g., an amine such as those
described above for the first initiator system), and optionally a
diaryliodonium simple or metal complex salt, chromophore-substituted
halomethyl-s-triazine, or halomethyl oxadiazole. Particularly preferred
visible light-induced photoinitiators include combinations of an
alpha-diketone, e.g., camphorquinone with additional hydrogen donors, and
optionally a diaryliodonium salt, e.g., diphenyliodonium chloride,
bromide, iodide or hexafluorophosphate.

[0098] The initiator system is present in an amount sufficient to provide
the desired rate of hardening (e.g., polymerizing and/or crosslinking)
For a photoinitiator, this amount will be dependent in part on the light
source, the thickness of the layer to be exposed to radiant energy, and
the extinction coefficient of the photoinitiator. Preferably, the
initiator system is present in a total amount of at least about 0.01
wt-%, more preferably, at least about 0.03 wt-%, and most preferably, at
least about 0.05 wt-%, based on the weight of the composition.
Preferably, the initiator system is present in a total amount of no more
than about 10 wt-%, more preferably, no more than about 5 wt-%, and most
preferably, no more than about 2.5 wt-%, based on the weight of the
composition.

[0099] The compositions may contain a surfactant system, i.e., one
surfactant or a mixture of two or more surfactants. These surfactants,
when used in small amounts may interact with other components of the
composition, such as an inorganic filler material, to enhance the
formation of a noncovalent three-dimensional structure. Such surfactants
can be nonionic, anionic, or cationic, as described in U.S. Pat. No.
7,674,850. The surfactant(s) can be copolymerizable with the resin system
or non-copolymerizable. A consideration in the choice of a surfactant
that can be used is the degree to which the ingredients of the system are
able to participate in hydrogen bonding.

[0100] Preferably, the total amount of surfactant system is at least about
0.05 wt-%, more preferably, at least about 0.1 wt-%, and most preferably,
at least about 0.2 wt-%, based on the total weight of the composition.
Preferably, the total amount of surfactant system is no more than about
5.0 wt-%, more preferably, no more than about 2.5 wt-%, and most
preferably, no more than about 1.5 wt-%, based on the total weight of the
composition.

[0101] The composition may additionally include optional agents such as
colorants (e.g., pigments conventionally used for shade adjustment),
flavorants, stabilizers (such as BHT), viscosity modifiers, and the like.
Such agents may optionally include reactive functionality so that they
will be copolymerized with the resin.

[0102] The composition can be shaped (to form a first shape) in a variety
of ways including, for example, extruding, injection molding, compression
molding, thermoforming, vacuum forming, and pressing. Typically, a
semi-finished shape is formed using a mold with a positive and negative
impression.

[0103] In some embodiments, the (e.g. preassembled) dental implant article
consists solely of the dental implant abutment integrated with (e.g.
embedded within) the (e.g. self-supporting) sufficiently malleable
material as described herein. In other embodiments, only the external
portion (e.g. the contacts the gingival tissue or internal tissue beneath
the gingival tissue) that is intended to be customized in shape for
tissue management comprises the (e.g. self-supporting) sufficiently
malleable material as described herein. For example, the implant abutment
may comprise a coating as previously described. As yet another example,
the dental implant article may comprise a different interior material
such as described in WO 2008/033893; incorporated herein by reference. In
one embodiment, the dental implant articles comprise an external layer
formed of a self-supporting hardenable preformed material, the external
layer having a dental implant article shape defined by an external layer
surface, the external layer defining an interior volume; and an interior
material disposed within the interior volume, wherein the interior
material is different than the external hardenable preformed material and
the interior material has a yield stress value of 100 dyn/cm2 or
greater. Such preformed multilayer dental implant articles may have two
or more layers of material to allow for accurate fit. Further, multilayer
dental articles can provide better esthetics, particularly for
embodiments wherein the dental implant article comprises tooth-shaped
supragingival exterior surfaces e.g., by having a multi-chromatic
appearance. Additionally such multilayer dental implant articles can
provide a better overall balance of mechanical properties, as well as
improved customization, including a more accurate fit to dental
preparations.

[0104] Generally, a preformed article of appropriate size and shape (the
first shape) is selected and custom shaped at a temperature of about
15° C. to 38° C. (preferably, about 20° C. to
38° C., which encompasses typical room temperatures and body
temperatures, and more preferably, at room temperature). This shaping can
be done by a variety of methods including applying pressure with fingers
or an instrument of choice (e.g., hand operation of dental composite
instrument), trimming, cutting, sculpting, grinding, etc. Once the
desired custom shape has been achieved, the article is hardened (e.g.,
cured) by exposing it to heat/radiation to cause activation of the
initiator system. This can be done either in a single step, or in
multiple steps with successive steps of custom shaping being done
in-between. One or more of these steps can be carried out in an
oxygen-free inert atmosphere or in vacuum. After the final shaping and
hardening steps, the hardened article can be further modified in shape by
grinding, trimming, etc., if desired. Once the final custom shape of the
article has been obtained, it can be polished, painted, or otherwise
surface treated, if required for the intended application. Preferably,
the final custom shaped articles (comprising tooth-shaped supragingival
exterior surfaces) prepared from the compositions do not need an
additional veneering material (e.g., a second material that provides a
desired appearance or property). For embodiments wherein the dental
implant article is a healing cap or other intermediate structure, a
second object, such as a crown may be attached to the custom shaped cured
article adhesively, mechanically, or by combination of both.

[0105] For the preparation of a dental implant article, an appropriate
shape and size of a preformed dental implant article is selected and
seated on the (e.g. temporary) implant anchor to determine the extent of
trimming and shaping required, optionally making marks on the cap. The
preformed dental implant article may be removed from the mouth, the
required shape and size adjustments are made by cutting, trimming,
shaping, etc., and then re-seated on the implant anchor where additional
shape adjustments are made to provide optimum custom fit, including at
least gingival fit. When the dental implant article comprises a
supragingival tooth-shaped structure the adjustments typically also
include lateral and occlusal fit. The preformed and reshaped dental
implant article can then be hardened, typically by exposing it to a
dental curing light for a few seconds, if desired, while in the mouth,
and then removing it carefully from the mouth and exposing it for final
cure to a curing light in a cure chamber, optionally in combination with
heat. Additional adjustments can be made by grinding, trimming, etc., if
required, and the finished dental implant article is polished and
cleaned.

[0106] The hardenable (e.g. self-supporting structures) dental implant
article can be prepackaged either individually, in multiple units, or as
an ensemble. Such packaging material should protect these products from
conditions that would activate the initiator system and thus cause
premature hardening, e.g., such as could result from exposure to light in
the case of a photoinitiator.

[0107] Various methods of manufacturing hardenable dental articles,
packaged hardenable dental articles, and methods of packaging hardenable
dental articles are known, such as described in U.S. Pat. No. 7,811,486;
incorporated herein by reference. Such method can be adapted to include
embedding a dental implant abutment during manufacture of the dental
implant article. For example, in one embodiment, the method comprises
providing a preformed dental implant abutment having a implant
anchor-receiving end and an opposing end and providing the opposing end
of the dental implant abutment within a mold cavity. The mold cavity is
suitably shaped for making a dental article, such as a healing cap
optionally comprising tooth-shaped supragingival exterior surfaces. Hence
the shape of the mold cavity of the mold body provides a net-shape or
near-net shape to the dental implant article.

[0108] The mold body may be formed in any suitable material or combination
of materials, e.g., metals, polymeric materials, etc. that provide
sufficient structural integrity to withstand the forming process as
described herein. In some instances, the mold body may be formed in
separable sections to facilitate removal of a hardenable dental implant
article formed therein. Also, the mold body may be made of or coated with
a material adapted to aid release of a hardenable dental implant article
from the interior surfaces of the mold cavity. For example, the interior
surfaces of the mold cavity may be coated with, e.g., fluorinated
polymers (e.g., PTFE, etc.), boron carbide, chrome, thin dense chrome,
chromium nitride, electroless nickel infused with fluorinated polymers,
modified tungsten disulfide (e.g., DICRONITE), etc.

[0109] The method further comprises filling the mold cavity with a
sufficiently malleable hardenable material. The mold cavity may be
temperature controlled to assist in the molding process by, e.g., heating
and/or cooling the temperature of the interior surfaces of the mold
cavity. In yet other variations, the mold cavity may be vented or
evacuated during the molding process to enhance molding. Ultrasonic or
other vibrational energy may also be used to enhance filling of the mold
cavity and/or assist with release the article from the mold cavity.
Hence, the sufficiently malleable material is typically subjected to an
elevated temperature and/or pressure and/or vibrational energy such that
the material is sufficiently flowable to take the shape of the mold
cavity. Since the sufficiently malleable material comprises curable
components such as those which can be photocured, the sufficiently
malleable material can be subsequently hardened by curing after
customizing of the shape (e.g. that contacts the healing tissue).

[0110] The dental implant abutment can be introduced either prior to or
after filling or partial filling of the mold cavity (e.g. but prior to
cooling).

[0111] In various embodiments, the manufacturing may involve molding a
hardenable dental material in a mold cavity that may be lined with a mold
liner. The use of a mold liner during manufacturing of hardenable dental
implant articles from hardenable dental materials may provide a number of
potential advantages such as assisting with release of the hardenable
dental implant article from the mold cavity; protecting the hardenable
dental implant article from contamination, enhancing the finish of the
hardenable dental implant article by providing a smooth finish on the
article during the forming process (if the liner itself is smooth), and
enhancing the finish of the dental implant article after hardening (if
the smooth inside surface of the mold liner is retained in intimate
contact with the outer surfaces of the hardenable dental implant article
during hardening).

[0112] If a mold liner is used in connection with the manufacturing of a
hardenable dental implant article, it may be preferred that the mold
liner be in intimate contact with the outer surfaces of the hardenable
dental implant article after release of the hardenable dental article
from the mold cavity. Alternatively, the hardenable dental article may
release from the mold liner after or during its removal from the mold
cavity.

[0113] One method of manufacturing comprises providing a mold cavity in a
shape of a hardenable dental article, wherein the mold cavity comprises
an opening; forcing a hardenable dental material into the mold cavity
through the opening; providing an outer liner between the hardenable
dental material and the mold cavity; and removing the hardenable dental
material and the outer liner from the mold cavity.

[0114] In one embodiment, the method comprises providing the outer liner
between the hardenable dental material and the mold cavity comprises
deforming the outer liner to form a pocket therein by forcing the
hardenable dental material into contact with the outer liner, wherein the
hardenable dental material is located within the pocket before forcing
the hardenable dental material into the mold cavity. Forcing the
hardenable dental material through the opening may comprise forcing a
core pin against the hardenable dental material, and a pin liner may be
provided between the hardenable dental material and the core pin.

[0115] The hardenable dental material typically has the shape of the
hardenable dental article. Further, the outer liner releases from the
hardenable dental article after or during removal from the mold cavity.
The (e.g. preassembled) hardenable dental article may comprise a mass of
hardenable dental material in the shape of a hardenable dental article,
wherein the hardenable dental article comprises a base and outer surfaces
extending from the base; and a package cover conforming to the outer
surfaces of the hardenable dental article. The package cover comprises a
polymeric film plastically deformed by the mass of hardenable dental
material. The package cover may include a flange extending away from the
hardenable dental article in order to provide a handle for removal of the
package cover.

[0116] In other embodiments, preformed pieces of sufficiently malleable
material can be modified for inclusion of the dental implant abutment.
The preformed pieces are suitably shaped for use as a healing cap
optionally comprising tooth-shaped supragingival exterior surfaces. Such
preformed pieces can be suitable shaped by use of molding (as just
described without embedding the opposing end of the implant abutment).
Alternatively such preformed pieces can be milled into such suitable
shape.

[0117] A hole can then be formed into the shaped (e.g. self-supporting)
piece of sufficiently malleable material. The opposing end of the dental
implant abutment can then be provided within the hole. The method can
comprise filling the remainder of the hole with a hardenable material. In
some embodiments, the hardenable material may be hardened (by curing)
when manufactured. In other embodiments, the hardenable material may be
concurrently hardened (by curing) concurrently with hardening (by curing)
of the sufficiently malleable material. Although the hardenable material
may comprise the same sufficiently malleable material, the hardenable
material is typically a different hardenable (e.g. composite) material.
This method is particularly useful when the "different hardenable
material" is a (e.g. relatively low viscosity) ceramic dental restoration
material or polymer-ceramic composite dental restoration material such as
Filtek Supreme Plus Flowable Restorative. Even though such dental
restoration material may differ from the sufficiently malleable material,
in this embodiment the material at the implant abutment interface is a
dental restoration material, rather than an adhesive.

[0118] Alternatively, but less preferred, a small hole can be formed into
the hardenable (e.g. self-supporting) piece of sufficiently malleable
material having an appropriate depth (about equal to the height of the
opposing end) and the implant abutment may simply be affixed within such
small cavity with a adhesive or a (e.g. permanent) cement. Various dental
adhesives and dental cements that are known to have good adhesion to
dental restoration materials may be employed. One suitable dental cement
is available from 3M ESPE, (St. Paul, Minn.) under the trade designation
"RelyX Unicem Self Adhesive Universal Resin Cement". However, since the
dental abutment is adhered to the sufficiently malleable outside of the
mouth, only the cured adhesive or cement need be biocompatible, rather
than both the uncured and cured adhesive or cement as is the case when a
(e.g. crown) restoration is adhesively bonded to an implant abutment.
Accordingly, various non-dental adhesive or cements can also be utilized.
In this embodiment, the interface between the opposing end of the implant
abutment and the restoration material comprises an adhesive and/or
cement.

[0119] In favored embodiments, the opposing end of the implant abutment is
embedded in the surrounding sufficiently malleable material such that the
interface between the implant abutment and the restoration material is
free of adhesive and/or cement.

[0120] In preferred embodiments, the sufficiently malleable portion of the
dental implant article described herein are self-supporting and thus the
package enclosing the dental implant article(s) predominantly serves a
typical "packaging function" such as protecting the dental implant
article from damage or contamination. In alternative embodiments, the
sufficiently malleable portion of the dental article are not
self-supporting. In this embodiment, the package additionally serves the
purpose of supporting the preformed shape of the sufficiently malleable
portion. For example the dental implant article may be provided in a
(e.g. disposable plastic) package wherein the portion of the package in
contact with the sufficiently malleable portion comprises the net-shape
or near-net shape of a healing cap optionally comprising tooth-shaped
supragingival exterior surfaces.

Healing Cap Formation

[0121] A wax model was formed in the shape of a healing cap for a
posterior tooth, the shape being further described in PCT/US2010/022961.
A silicone impression material (3M Imprint II Wash Material, Regular
Viscosity, available from 3M ESPE), was used to create a two-part mold
having the negative shape of the wax model. The parting line of the mold
was along the widest horizontal circumference of the healing cap. Several
malleable, curable crowns (Protemp Crowns, Temporization Material-Molar
Upper Large, available from 3M ESPE), formed from a malleable,
photocurable composite material, were heated to 60 deg. C. and combined
to make a bulk paste material. About 0.74 g. of the warmed paste material
was placed into the mold, which was then closed around the material and
allowed to cool for 3 hrs. at 4 deg. C. After cooling, the mold was
opened and the finished healing cap was removed.

Test Method

[0122] The healing caps were pressed around the portion of an abutment
intended to receive the restoration (Neoss Matrix Aesthetic Abutments,
compatible with Straumann 4.8 mm implants, available from Neoss Inc.,
Woodland Hills, Calif.). The healing cap was then cured for 60 sec. using
an Elipar S10 Curing Light (3M ESPE), while slowly rotating the healing
cap to irradiate all sides. A Straumann implant analog (Straumann USA,
Andover, Mass.) was attached to the base of the abutment with the
corresponding screw. The abutment having the attached healing cap and
implant analog was mounted in an Instron (Model 5500R, Instron Corp.,
Canton, Mass.). The implant analog was clamped in the stationary jaws of
the Instron. To avoid the griper jaws crushing the healing cap, a custom
steel plate having a circular hole slightly larger than the abutment but
smaller than the healing cap was used to encircle the base of the
abutment with the healing cap resting on the plate. The edges of the
steel plate were gripped in the pulling jaws of the Instron and the jaws
were pulled apart at a crosshead speed of 1.0 mm/min, thus applying the
pulling force to the base of the healing cap.

EXAMPLE 1

[0123] A healing cap was attached to an abutment as received with no
further surface treatment, and cured. Duplicate tests were performed, and
the forces required to pull the healing cap from the abutment were 2.1 kg
and 2.8 kg.

EXAMPLE 2

[0124] A healing cap was attached to an abutment as received that had been
coated with Filtek Supreme Plus Flowable Restorative, A 3.5 shade, (3M
ESPE), and cured. Duplicate tests were performed, and the forces required
to pull the healing cap from the abutment were 8.9 kg and 15.9 kg.

EXAMPLE 3

[0125] A healing cap was attached to an abutment that had been sandblasted
at 2 bars of pressure with 50 um aluminum oxide using a Vaniman Sandstorm
XL (Vaniman Co., Fallbrook, Calif.), the nozzle being positioned about
1/2'' from the abutment, leaving a roughened, matte surface on the metal,
and cured. Duplicate tests were performed, and the forces required to
pull the healing cap from the abutment were 13.5 kg and 19.1 kg.

EXAMPLE 4

[0126] A 0.75 g piece of Filtek P60 Posterior Restorative, A3 shade
(available from 3M ESPE) was placed in the mold described under Healing
Cap Formation, which was then closed around the material. Both the dental
material and the mold were at room temperature. The filled mold was
allowed to cool for 2 hours at 4 deg. C., after which the mold was opened
and healing cap was removed.

[0127] The (opposing) portion of an abutment intended to receive the
restoration (Neoss Matrix Aesthetic Abutments, compatible with Straumann
4.8 mm implants, available from Neoss Inc., Woodland Hills, Calif.) was
sandblasted according to Example 3. Then the healing cap was pressed
around the sandblasted portion of the abutment.